In physical cosmology, cosmic inflation, cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch lasted from 10−36 seconds after the conjectured Big Bang singularity to some time between 10−33 and 10−32 seconds after the singularity. Following the inflationary period, the universe continued to expand, but at a slower rate. The acceleration of this expansion due to dark energy began after the universe was already over 7.7 billion years old (5.4 billion years ago).[1]
https://en.wikipedia.org/wiki/Inflation_(cosmology)
In physical cosmology, Big Bang nucleosynthesis (abbreviated BBN, also known as primordial nucleosynthesis, archeonucleosynthesis, archonucleosynthesis, protonucleosynthesis and paleonucleosynthesis)[1] is the production of nucleiother than those of the lightest isotope of hydrogen (hydrogen-1, 1H, having a single proton as a nucleus) during the early phases of the Universe. Primordial nucleosynthesis is believed by most cosmologists to have taken place in the interval from roughly 10 seconds to 20 minutes after the Big Bang,[2] and is calculated to be responsible for the formation of most of the universe's helium as the isotope helium-4(4He), along with small amounts of the hydrogen isotope deuterium (2H or D), the helium isotope helium-3 (3He), and a very small amount of the lithium isotope lithium-7(7Li). In addition to these stable nuclei, two unstable or radioactive isotopes were also produced: the heavy hydrogen isotope tritium (3H or T); and the beryllium isotope beryllium-7 (7Be); but these unstable isotopes later decayed into 3He and 7Li, respectively, as above.
Essentially all of the elements that are heavier than lithium were created much later, by stellar nucleosynthesis in evolving and exploding stars.
https://en.wikipedia.org/wiki/Big_Bang_nucleosynthesis
The gravitational wave background (also GWB and stochastic background) is a random gravitational-wave signal potentially detectable by gravitational wave detection experiments. Since the background is supposed[by whom?] to be statistically random, it has yet been researched only in terms of such statistical descriptors as the mean, the variance, etc.
https://en.wikipedia.org/wiki/Gravitational_wave_background
The cosmic microwave background (CMB, CMBR), in Big Bang cosmology, is electromagnetic radiation which is a remnant from an early stage of the universe, also known as "relic radiation".[1] The CMB is faint cosmic background radiation filling all space. It is an important source of data on the early universe because it is the oldest electromagnetic radiation in the universe, dating to the epoch of recombination. With a traditional optical telescope, the space between stars and galaxies (the background) is completely dark. However, a sufficiently sensitive radio telescope shows a faint background noise, or glow, almost isotropic, that is not associated with any star, galaxy, or other object. This glow is strongest in the microwave region of the radio spectrum. The accidental discovery of the CMB in 1965 by American radio astronomers Arno Penzias and Robert Wilson[2][3] was the culmination of work initiated in the 1940s, and earned the discoverers the 1978 Nobel Prize in Physics.
CMB is landmark evidence of the Big Bang origin of the universe. When the universe was young, before the formation of stars and planets, it was denser, much hotter, and filled with an opaque fog of hydrogen plasma. As the universe expanded the plasma grew cooler and the radiation filling it expanded to longer wavelengths. When the temperature had dropped enough, protons and electrons combined to form neutral hydrogen atoms. Unlike the plasma, these newly conceived atoms could not scatter the thermal radiation by Thomson scattering, and so the universe became transparent.[4] Cosmologists refer to the time period when neutral atoms first formed as the recombination epoch, and the event shortly afterwards when photons started to travel freely through space is referred to as photon decoupling. The photons that existed at the time of photon decoupling have been propagating ever since, though growing less energetic, since the expansion of space causes their wavelength to increase over time (and wavelength is inversely proportional to energy according to Planck's relation). This is the source of the alternative term relic radiation. The surface of last scattering refers to the set of points in space at the right distance from us so that we are now receiving photons originally emitted from those points at the time of photon decoupling.
https://en.wikipedia.org/wiki/Cosmic_microwave_background
The cosmic neutrino background (CNB or CνB[a]) is the universe's background particle radiation composed of neutrinos. They are sometimes known as relic neutrinos.
The CνB is a relic of the Big Bang; while the cosmic microwave background radiation(CMB) dates from when the universe was 379,000 years old, the CνB decoupled(separated) from matter when the universe was just one second old. It is estimated that today, the CνB has a temperature of roughly 1.95 K.
As neutrinos rarely interact with matter, these neutrinos still exist today. They have a very low energy, around 10−4 to 10−6 eV.[1][2] Even high energy neutrinos are notoriously difficult to detect, and the CνB has energies around 1010 times smaller, so the CνB may not be directly observed in detail for many years, if at all.[1][2] However, Big Bang cosmology makes many predictions about the CνB, and there is very strong indirect evidence that the CνB exists.[1] [2]
https://en.wikipedia.org/wiki/Cosmic_neutrino_background
In physics, mirror matter, also called shadow matter or Alice matter, is a hypothetical counterpart to ordinary matter.[1]
https://en.wikipedia.org/wiki/Mirror_matter
In modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding particles in "ordinary" matter. Minuscule numbers of antiparticles are generated daily at particle accelerators—total production has been only a few nanograms[1]—and in natural processes like cosmic ray collisions and some types of radioactive decay, but only a tiny fraction of these have successfully been bound together in experiments to form anti-atoms. No macroscopic amount of antimatter has ever been assembled due to the extreme cost and difficulty of production and handling.
Theoretically, a particle and its anti-particle (for example, a proton and an antiproton) have the same mass, but opposite electric charge, and other differences in quantum numbers. For example, a proton has positive charge while an antiproton has negative charge.
https://en.wikipedia.org/wiki/Antimatter
In theoretical physics, negative mass is a type of exotic matter whose mass is of opposite sign to the mass of normal matter, e.g. −1 kg.[1][2] Such matter would violate one or more energy conditions and show some strange properties such as the oppositely oriented acceleration for negative mass. It is used in certain speculative hypothetical technologies, such as time travel to the past,[3]construction of traversable artificial wormholes, which may also allow for time travel, Krasnikov tubes, the Alcubierre drive, and potentially other types of faster-than-light warp drives. Currently, the closest known real representative of such exotic matter is a region of negative pressure density produced by the Casimir effect.
https://en.wikipedia.org/wiki/Negative_mass
Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe.[1] Its presence is implied in a variety of astrophysicalobservations, including gravitational effects that cannot be explained by accepted theories of gravity unless more matter is present than can be seen. For this reason, most experts think that dark matter is abundant in the universe and that it has had a strong influence on its structure and evolution. Dark matter is called dark because it does not appear to interact with the electromagnetic field, which means it does not absorb, reflect or emit electromagnetic radiation, and is therefore difficult to detect.[2]
https://en.wikipedia.org/wiki/Dark_matter
The Mirror Universe is a parallel universe in which the plots of several Star Trek television episodes take place. It resembles the fictional universe in which the Star Trek television series takes place, but is separate from the main universe.[1][2] The Mirror Universe has been visited in one episode of Star Trek: The Original Series,[3] five episodes of Star Trek: Deep Space Nine,[1][4] a two-part episode of Star Trek: Enterprise[5] and a storyline in Star Trek: Discovery, as well as several non-canon Star Trek tie-in works. It is named after "Mirror, Mirror", the original series episode in which it first appeared.[6]
https://en.wikipedia.org/wiki/Mirror_Universe
Science (physics and cosmology)[edit]
A parallel universe, also known as an alternate universe or alternative universe, or, alternate or alternative reality, is a hypothetical self-contained plane of existence, co-existing with one's own. The sum of all potential parallel universes that constitute reality is often called a “multiverse".
- Multiverse, the set of multiple universes
- The many-worlds interpretation of quantum physics
neutronium
Neutronium (sometimes shortened to neutrium,[1] also referred to as neutrite[2]) is a hypothetical substance composed purely of neutrons. The word was coined by scientist Andreas von Antropoff in 1926 (before the 1932 discovery of the neutron) for the hypothetical "element of atomic number zero" (with zero protons in its nucleus) that he placed at the head of the periodic table (denoted by dash, no element symbol).[3][4] However, the meaning of the term has changed over time, and from the last half of the 20th century onward it has been also used to refer to extremely dense substances resembling the neutron-degenerate mattertheorized to exist in the cores of neutron stars; hereinafter "degenerate neutronium" will refer to this.
Science fiction and popular literature have used the term "neutronium" to refer to an imaginary highly dense phase of matter composed primarily of neutrons, with properties useful to the story.
https://en.wikipedia.org/wiki/Neutronium
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